I believe the barrier is not to keep them in, but instead to designate the "protest area." Did I mention that I think protests are worthless? They try to draw attention to their cause, but most people are apathetic, and won't remember next week.
As for the pepper spraying, maybe the cops were afraid of the trim-haired Wiccan in the prairie skirt. Maybe she was about to cast a spell on their asses, so they had to act. That's the aggression they were anticipating.
I think one major insight that Neal Gabler underestimates is the human mind's ability to filter "noise." As DOtz pointed out above, "Ninty percent of everything is crap," and our eyes/minds filter that crap out. It's like banner ads on websites. I don't even notice them, unless it's something that my mind thinks I need, then I look at the ad.
If nothing else, the Age of the Internet/Information or whatever you want to call it, has given us the ability to quickly, mentally sort what is relevant, and what is noise.
Sure, there are thousands of tweets, wall postings, and blog entries every day, so much so that we couldn't possibly read them all. Our filter kicks in and we only see what we need to see.
I don't think that the US government has been giving North Korea the time of day. Perhaps that's why they are 50-75 years behind the rest of the civilized world. I vote that the US government start giving North Korea the time of day, so they can join us in this century.
If anyone here watched Indy racing over the past few seasons, you'll know about "side-by-side." Since the race never stops, even during a yellow flag situation, they go to commercial and use a split screen. They certainly do go to commercial while the race is still going (when there is an extended green flag period), and they show the continuing race along side the commercials. I actually watch the ads. Why doesn't anyone else do that? Other sports don't have specific time out periods...golf, other forms of auto racing, long-distance running...